HLA-B57

HLA-B57 is a human leukocyte antigen serotype within HLA-B serotype group. The serotype is determined by the antibody recognition of antigen B*57. This broad antigen group also includes the more specific HLA-B*5701, B*5702, B*5703, and B*5704 antigens, among others. HLA-B57 is associated with slow progression to AIDS in HIV-infected individuals and a hypersensitivity reaction to the HIV medication abacavir.

Structure and Function

HLA-B57 is a part of the HLA-B series of proteins, which are integral to the immune system. These proteins are found on the surface of cells and play a crucial role in the immune system's recognition of foreign substances. HLA-B57, like other HLA proteins, is involved in presenting peptides from inside the cell to the immune system.

Clinical Significance

HLA-B57 has been found to be associated with a slower progression to AIDS in individuals infected with HIV. This is thought to be due to the ability of HLA-B57 to present a broader range of HIV peptides to the immune system, allowing for a more effective immune response.

In addition, HLA-B*5701, a specific antigen within the HLA-B57 group, is associated with a hypersensitivity reaction to the HIV medication abacavir. This reaction can be severe and life-threatening, and individuals with the HLA-B*5701 antigen are generally advised to avoid abacavir.

Testing and Treatment

Testing for the presence of HLA-B57 and specifically HLA-B*5701 is recommended for individuals who are HIV positive and considering treatment with abacavir. This can be done through a blood test.

If an individual tests positive for HLA-B*5701, alternative HIV medications should be considered to avoid the risk of a hypersensitivity reaction.

See Also

• Human leukocyte antigen
• AIDS
• Abacavir
• Immune system